This invention relates to an essentially cholesterol-free egg product and a process for making the same.
One of the major sources of food protein to man is derived from eggs. Over six billion pounds of eggs are consumed in the United States each year. Almost all eggs are consumed after cooking, primarily as fried eggs. Eggs may also be boiled, poached, baked or used as an ingredient in cakes, pies, sauces and other dishes. The unique functional properties of eggs, especially egg protein, gives cooked egg an eating quality unique among food proteins.
The liquid protein of shell eggs consists of two portions, the yolk and the liquid egg white. The yolk makes up 39 percent of the freshly cracked egg and contains about 45 percent solids, 14 percent protein, 30 percent fat and 1.5 percent cholesterol. When the term egg yolk is used, this is the product meant. The liquid egg white makes up about 61 percent of the whole egg and contains about 12 percent solids, 10 percent protein, only a trace of fat and no cholesterol. Liquid whole eggs containing the natural amounts of liquid yolk and liquid egg whites contain 25 percent solids, 75 percent water, 12 percent protein, 11 percent fat and about 0.6 percent cholesterol. The liquid whole eggs, liquid egg yolks and liquid egg whites can be dried to produce egg products containing less than 10 percent water. These dried egg products are known as whole egg solids, yolk solids and egg white solids, respectively. These dried egg products have approximately the same composition as the liquid products except for a lesser amount of water.
In recent years there has been shown that the consumption of cholesterol may be related to atherosclerosis. Although there is conflicting evidence on this relationship, the medical profession has advised patients with a tendency to have a high blood cholesterol or any symptoms of atherosclerosis to limit their consumption of cholesterol. Many nutritionists advise older people to lower their intake of dietary cholesterol.
Whole eggs are one of man's richest sources of high quality protein. However, whole eggs are also a rich source of dietary cholesterol containing approximately 550 mg. of cholesterol per 100 grams which is the approximated weight of the edible portion of two large whole eggs. Liquid egg whites contain no cholesterol. Liquid egg whites can be separated from liquid yolks and contains approximately 10 percent protein. The protein quality of liquid egg whites is almost equal to liquid whole eggs.
The unique cooked eating quality of eggs can be attributed primarily to the egg protein. However, the yolk also contains fats and natural emulsifiers like lecithin. The eating quality of liquid yolk and whites are different when the yolk and whites are cooked separately. This difference is observed when a freshly cracked egg is carefully placed in a frying pan without breaking the yolk. As the heat is applied under the frying pan the liquid white becomes firm and if heated too long will become very firm and have a rubbery texture. The yolk in the frying pan under the same heating conditions will firm more slowly and not develop the rubbery texture of egg whites. This difference in eating quality can be attributed to the different types of proteins in the two egg fractions and the pressure of oil and emulsifiers in the egg yolk. Blending the yolk and white in preparing cooked scrambled eggs minimizes the development of the rubbery texture of overcooked egg whites.
The most important characteristic of a cooked egg product is the proper texture. When cooked egg product is referred to herein, scrambled eggs is meant. The texture of scrambled eggs from a whole egg is generally considered to be firm, scrambling up to form large curds when a minimal of stirring is used. The whole scrambled egg has a firm-like mouthfeel without being mushy or mealy.
It has been found that there are tremendous variations in cooking operations in the cooking of liquid egg compositions. Some people cook the liquid composition in a skillet with high heat. Under such conditions, some cholesterol-free egg compositions will form fairly firm curds and have a firm mouthfeel. On the other hand, these same products when cooked in a double boiler will product a cooked egg product having a gelatinous mouthfeel. Clearly, such products can be expected to be unacceptable to many people and experience has shown this to be so.
It is important in a cholesterol-free egg product to have a composition which will cook to a texture and appearance of scrambled whole egg whether cooked quickly under fry pan heating conditions above 212.degree. F. or cooked slowly in a double boiler at temperatures under 212.degree. F. The better the cooked egg texture and appearance of cholesterol-free egg products prepared between these two extremes, the better the cooking tolerance. By cooking tolerance of a cholesterol-free egg product is meant the ability of the formulation to cook to a satisfactory texture and appearance whether cooked at temperatures either under 212.degree. F. (double boiler) or over 212.degree. F. (skillet).
In the Seeley et al U.S. Pat. No. 3,987,212, this improved cooking tolerance is obtained by making a product based upon liquid egg whites but containing an additional amount of egg white solids sufficient to provide about 12.5 to about 16% egg white solids in the liquid product and non-egg ingredients comprising non-fat milk solids (about 1 to about 3.5%) and vegetable gum (about 0.25 to about 1.3%) in the form of carboxymethyl cellulose, the product containing about 80 to about 85% water. The additional amount of egg white solids (greater than that contained in liquid egg whites) and the non-egg ingredients are responsible for a substantially improved cooking tolerance of the product, especially when cooked in a double boiler at temperature less than 212.degree. F. This prior art product may also contain small amounts of an anti-foam agent in the form of mono and diglycerides of fat-forming fatty acids as well as small amount of flavor enhancer preferably in the form of a yeast extract.